Input devices including proximity sensor devices (also commonly called touchpads or touch sensor devices) are widely used in a variety of electronic systems. A proximity sensor device typically includes a sensing region, often demarked by a surface, in which the proximity sensor device determines the presence, location and/or motion of one or more input objects. Proximity sensor devices may be used to provide interfaces for the electronic system. For example, proximity sensor devices are often used as input devices for larger computing systems (such as opaque touchpads integrated in, or peripheral to, notebook or desktop computers). Proximity sensor devices are also often used in smaller computing systems (such as touch screens integrated in cellular phones).
Presently known capacitive sensing devices are limited in their ability to effectively synchronize the touch controller with the display controller. The time delay between touch data collection and the subsequent processing and display of the touch data is referred to as latency. Low levels of constant latency are generally imperceptible to the user. However, variations in latency can cause the display to appear jerky or clumsy as the on-screen user interface element (e.g., a cursor, scrolling or dragging feature) imperfectly tracks or follows the user's finger movement. This “judder” tends to compromise the perceived smoothness of the user interface experience. Attempts to synchronize the acquisition of touch data with the display refresh rate have had limited success inasmuch as the touch screen controller typically does not have direct access to the display screen controller. Thus, there exists a need for capacitive sensing devices that mitigate or eliminate judder without requiring additional hardware connections between the touch screen controller and the display controller.